#include<iostream>
#include <stdio.h>
#include<string>
using namespace std;
int get_second(int h,int m,int s)
{
    return h*3600+m*60+s;
}
int get_time()
{
    string line;
    getline(cin,line);
    if(line.back()!=')')line+=" (+0)"; 
    int h1,m1,s1,h2,m2,s2,d;
    sscanf(line.c_str(),"%d:%d:%d %d:%d:%d (+%d)",&h1,&m1,&s1,&h2,&m2,&s2,&d);
    return get_second(h2,m2,s2)-get_second(h1,m1,s1)+d*24*3600;
}
int main()
{
    int n=0;
    cin>>n;
    string line;
    getline(cin,line);
    while(n--)
    {
        int time=(get_time()+get_time())/2;
        int hour=time/3600,min=time%3600/60,sec=time%60;
        printf("%02d:%02d:%02d\n",hour,min,sec);
    }
    return 0;
}